Energizable surgical tools present a safety hazard to the patient and operating room personnel if the tools are unintentionally activated. Accidental contact with an energized surgical tool can result in burns and other tissue damage. The present design of those instruments has not entirely eliminated this hazard, and accidents of this nature may occur under unexpected circumstances.
In a surgical theater, energized surgical tools are used by a surgeon to operate on a patient's tissue and organs. Typical energy sources include high frequency electrical current, laser illumination, and ultrasonic vibration. A switch is typically provided to direct this energy to the surgical tool. The switch may be located on the handpiece of the surgical tool, or at another location such as near the surgeon's foot. Normally the switch is open and when the surgeon wishes to operate the tool, the switch is manually closed. The simple mechanical action on the switch is sufficient to direct energy to the tool.
During surgery, surgical tools are often placed near the surgical site for easy access. This placement may increase the risk of accidentally bumping or keying the switching mechanism. Furthermore, a surgeon may unintentionally activate the tool while it is held during surgery. For example an electrosurgical pencil may be activated by accidental pressure on a rocker switch or foot pedal.
Certain surgical tool designs have attempted to address the problem of inadvertent activation. U.S. Pat. No. 4,418,692 discloses an electrosurgical tool for use in laparoscopic tubal cauterization with electrodes disposed to first grasp tissue. The electrodes can not become energized unless they are in a closed configuration, i.e. about the tissue to be electrosurgically treated. This prevents premature activation of the electrodes since they are normally held in an open configuration. This patent does not address the more general design issue of inadvertently activating any energizable surgical tool.
U.S. Pat. No. 5,035,695 discloses an extendable electrocautery surgery apparatus with an interlock switch. The interlock switch is disposed to cut off the application of all electrical signals when the electrode conductor is in a retracted configuration. There are additional switches which select between cutting and coagulation waveforms. These switches are shrouded against inadvertent activation when the electrode conductor is in a retracted configuration.
U.S. Pat. No. 4,911,159 discloses an electrosurgical instrument with an on/off switch that directs power to the electrode conductor. The switch may be on the handpiece of the instrument or on a separate foot-operated device. In addition, there are separate switches for selecting cut or coagulation waveforms.
None of the above disclosures teaches the safety apparatus of the present invention, which may be used in connection with any energizable surgical device.